By: Pacific Corrugated Pipe Co.
After heavy rains in Northern California, the side of a hill, on the edge of a parking lot, gave way creating a sinkhole approximately 250’ in diameter. This section of Wolf Creek, directly at the bottom of the hole, handles about ¼ of Grass Valley’s stormwater drainage during the heavy season. After realizing there was a significant sinkhole issue, city engineers, contractors and Pacific Corrugated Pipe worked together to create a solution.
Upon inspection it was found that 20-30′ trees had been sucked into the upslope opening of the culvert – creating a blockage. Engineers believed that this blockage is what caused the large sinkhole to form.
The existing culvert was 90 feet below the finished grade so about 10,000 cubic yards of dirt had to be excavated to expose the issue and take out the old pipe. The 39 feet of 72” pipe was used as a riser to connect the 150’ of 90” pipe to Little Wolf Creek. One 45º elbow and one 90” x 72” tee was utilized to make the proper connection and ensure an effective solution for long term stability of the area.
For more information visit Pacific Corrugated Pipe at their website.